Renin is a natural enzyme which is released into the blood from the kidney. It cleaves its natural substrate, angiotensinogen, releasing a decapeptide, angiotensin I. This is in turn cleaved by converting enzyme in the lung, kidney and other tissues to an octapeptide, angiotensin II. Angiotensin II raises blood pressure both directly by causing arteriolar constriction and indirectly by stimulating release of the sodium-retaining hormone aldosterone from the adrenal gland causing a rise in extracellular fluid volume. Inhibitors of renins have been sought as an agent for control of hypertension, congestive heart failure, and hyperaldosteronism.
The present invention concerns a novel series of branched-backbone peptides which inhibit renin. It also concerns pharmaceutical compositions containing these novel peptides, methods of treating renin-associated hypertension, congestive heart failure, and hyperaldosteronism, as well as the use of the peptides as diagnostic tools, and the methods for preparing the peptides.